The A-7th chord sends a chill down my spine. I’m guessing it’s an A-7th because it has that open, resonating feel to it. It’s played several times during “Think It Over” by The Call. And every time it’s strummed, it pins the words down to something deeply emotional. Listening to it recently I couldn’t help but jump up and google Michael Been, the writer and bass player behind most of The Call’s songs. I so clearly remember seeing them perform at Hammerjack’s, a nightclub in downtown Baltimore,  near the docks. You had to be careful at Hammerjack’s because a few steps in the wrong direction – and you were in…